V.22 bis Modem with AT Commands
CMX866
S-Register
Description
Reg Range Units
Default
0-255
0-255
0-255
S19
S20
S21
Reserved – Reserved for test functions
Reserved
Hex
10
Loopback and Power States - controls the operation of
remote loopback and operational states:
Bit 4 - Remote loopback, 0 Disabled, 1 Enabled
(See &Tn command)
Bit 6 - Powersave state, 0 Not powersaved,
1 Powersaved
Bit 7 - 'Zero-Power' state, 0 Not 'Zero-Power',
1 'Zero-Power'
All other bits Reserved
0-255
Hex
C0
S22
Calling and Response Characteristics (see section
1.5.4.1):
Bit 4-0 - Reserved
Bit 7-5 - Calling and Response Characteristics:
000 Ignore Dial Tone and Busy Tone (ATX0),
100 Ignore Busy Tone, wait for Dial Tone (ATX1),
101 Ignore Dial Tone, wait for Busy Tone (ATX2),
110 Wait for Dial Tone and Busy Tone (ATX3)
0-255
0-255
Hex
Hex
00
S23
S24
Guard Tone Selection (see section 1.5.4.1):
Bit 5-0 - Reserved
Bit 7-6 - Guard Tone Activity:
00 Disabled (AT&G0),
11 Enabled, guard tone = 550Hz (AT&G1)
10 Enabled, guard tone = 1800Hz (AT&G2)
A9
Equaliser, DCD and DTR status (see section 1.5.4.1):
Bit 0 - Reserved. Permanently set to 1
Bit 1 - Fixed Compromise Equaliser, 0 Enabled, 1
Disabled
Bit 2 - Auto-Equaliser, 0 Disabled, 1 Enabled
Bit 3 - DCDN pin function, 0 DCDN always low, 1
DCDN follows inverse of carrier
Bit 5-4 - DTRN pin function,
00 Ignore DTRN signal (AT&D0),
01 Go to Command mode when low to high
transition has been qualified (AT&D1)
10 Go on-hook then go to Command mode when
low to high transition has been qualified (AT&D2)
Bit 6 - Reserved for use with the V.23 or Bell 202
turnaround function (used by the ATRO command)
Bit 7 - Fallback mechanism from V.22bis to V.22
(equivalent to ATN1 command), 0 Disabled, 1
Enabled
ã 2004 CML Microsystems Plc
27
D/866/4
CMLMICRO [ CML MICROCIRCUITS ]
